This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A116240 #2 Mar 30 2012 17:40:40 %S A116240 93,454,538,993,7664,9993,72720,99993,356428,643564,999993,9090909, %T A116240 9999993,35294117,64705875,99999993,335664328,664335664,684210519, %U A116240 818181818,838056673,846153846,866028701,980125138,999999993 %N A116240 n times n+9 gives the concatenation of two numbers m and m-8. %Y A116240 Cf. A116109, A116231, A116239, A116245. %K A116240 nonn,base %O A116240 1,1 %A A116240 _Giovanni Resta_, Feb 06 2006